US traders reacted positively to weekend comments from Federal Reserve head Janet Yellen on the bank’s monetary policy.

Yellen told the Fed’s annual symposium in Jackson Hole, Wyoming, that despite a sharp fall in joblessness there was “considerable uncertainty about the level of employment” in the economy. That was taken as signalling her commitment to raise rates late next year, rather than earlier as some analysts and policymakers would like.

The prospect of the Fed continuing its accommodative policy cheered US investors, who sent the S&P 500 to a record level.

The S&P 500 rose 0.48 percent but ended a tad below the 2,000 level after breaching it for the first time earlier in the day.

The Dow added 0.44 percent and the Nasdaq jumped 0.41 percent to its best close since the dot-com crash 14 years ago.

Asian markets were unable to extend their gains from Monday, however, and the dollar lost its momentum after hitting a seven-month high against the yen.

In Japanese trade the greenback fetched 103.90 yen in early Asian trade, compared with 104.01 yen late in New York and well off the 104.18 yen in Tokyo earlier Monday.

The euro bought $1.3182 and 137.26 yen Tuesday against $1.3193 and 137.23 yen in US trade.

The single currency was also under pressure after European Central Bank chief Mario Draghi hinted that he could embark on fresh monetary easing measures to kickstart the eurozone, while an index of German business confidence hit a 13-month low.

On oil markets West Texas Intermediate for October delivery rose 17 cents to $93.52 while Brent crude for October gained 13 cents to $102.78.

Gold traded at $1,278.60 an ounce at 0210 GMT compared to $1,277.98 an ounce late Monday.